9k1. 3D Viewer Tools

9k1a. Minimize

9k1b. Large Surface

9k1c. Middle Surface

9k1d. Small Surface

9k1e. Opaque

9k1f. Samples

9k1g. Clear BG

9k1h. Sliced

9k1i. Wireframe

9l. Help

10. The Primatte Algorithm

10a. How Primatte works...

10b. How Primatte RT+ works...

10c. How Primatte RT works...

11. If you have trouble…

12. Request a NodeLock License

Proprietary Notices:

Primatte is distributed and licensed by IMAGICA Corp. of America, Los Angeles, CA, USA

Primatte was developed by IMAGICA Corp., Tokyo, Japan

Primatte is a trademark of IMAGICA Corp., Tokyo, Japan

1. Installation Information:

~~If you received a CD...~~

(NOTE: Not applicable)

If you downloaded the Primatte plug-in from the www.primatte.com web or ftp site on the Internet:

If you are on a Windows system:

A. Unzip the Primatte for OFX plug-in files into a temporary directory.

B. Double-click on the Setup.exe icon to install the plug-in.

C. Go to Section 2. Getting and Installing a License Key.

If you are on a LINUX or IRIX system:

A. Login as 'root'

B. Go to the folder with the downloaded plug-in.

C. Unzip the file by typing: gunzip PrimatteWEBInstaller_linux32_ofxv2.tar.gz

D. Untar the file by typing: tar -xf PrimatteWEBInstaller_linux32_ofxv2.tar

E. Go to the primatte folder: cd primatte

F. Install the plug-in: ./install.pl

NOTE: This will install an HTML manual at /usr/local/PRIMATTE/OFX/doc/Prim_Manual.html

NOTE: The plug-in will be installed at /usr/OFX/Plugins/Primatte.ofx.bundle/Contents/Linux-x86/Primatte.ofx.

G. Go to Section 2. Getting and Installing a License Key.

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2. Getting and Installing a License Key

▪ All versions of Primatte for OFX use a NodeLocked license scheme. The NodeLock license is locked to single machine. This section of the manual describes how to install and set up the Primatte for OFX license system. This section also describes how to request a license key password file and instructions on how to activate the Primatte software once you have the license key.

▪ The Primatte license key file is provided to you from IMAGICA Corp. of America and may have been FAXed to you or e-mailed.

How To Get a License Key

▪ To request a license key from IMAGICA, you have to determine the MacAddress (also known as the NIC - Network Interface Card identification).

Find the MacAddress on a Windows system:

▪ After downloading and installing the Primatte for OFX plug-in, you will find a Windows utility named GetMac.exe in the C:\Program Files\PRIMATTE\OFX\. If you execute this utility on the host system, it will return the MacAddress that IMAGICA needs to generate your Primatte for OFX license key.

Find the MacAddress on a Linux system:

▪ After downloading and installing the Primatte for OFX plug-in, you will find a Linux utility named GetMac in the /usr/local/PRIMATTE/OFX/ folder. If you execute this utility on the host system, it will return the MacAddress that IMAGICA needs to generate your Primatte for OFX license key.

Find the MacAddress on an SGI IRIX system:

▪ After downloading and installing the Primatte for OFX plug-in, you will find an IRIX utility named GetMac in the /usr/local/PRIMATTE/OFX/ folder. If you execute this utility on the host system, it will return the MacAddress that IMAGICA needs to generate your Primatte for OFX license key.

Find the MacAddress on an Apple OSX system:

▪ After downloading and installing the Primatte for OFX plug-in, you will find a Mac utility named GetMac in the /usr/local/PRIMATTE/OFX/ folder. If you execute this utility on the host system, it will return the MacAddress that IMAGICA needs to generate your Primatte for OFX license key.

What to do with the MacAddress

▪ A temporary license application form is provided on the last page of this document. Fill out the form and send it to IMAGICA and they will send you a temporary license key for your machine. You can also log onto the IMAGICA web site (http://www.primatte.com) and request a license via e-mail.

How To Install a NodeLock Primatte license:

▪ The NodeLock license you receive from IMAGICA will consist of a string of lowercase alpha characters and numbers. The length will depend on whether it is a temporary or permanent license.

Example of a permanent license string: 42abd8a5c1d13000|0750

What you will be sent:

# Permanent Primatte for Primatte AvidDS 7.5 (Client Workstation) (NodeLocked)
# --------------------------------------
DSPRIM_LICENSE : 42abd8a5c1d13000|0750
# (this license is valid for MacAddress 12-12-12-12-12-12)
# --------------------------------------

Example of a temporary license string: 44ba8c60068bd400|0750+2006042

What you will be sent:

# 30-day Temporary Primatte for Primatte AvidDS 7.5 (Client Workstation) (NodeLocked)
# --------------------------------------
DSPRIM_LICENSE : 44ba8c60068bd400|0750+20060426
# (this license is valid for MacAddress 12-12-12-12-12-12)
# (this license is valid until 04/26/2006)
# --------------------------------------

NOTE: The following instructions assume you have downloaded and installed the plug-in.

Install the license on a Windows system:

▪ In the C:\Program Files\PRIMATTE\OFX\license\ directory you will find a Windows utility named RegLic.exe. Once you have your license, execute the RegLic.exe program. Enter the Registration License that was e-mailed to you in the window area provided (it is usually easier to copy and paste the license from your e-mail to avoid transcription errors). Click on the Registration button and the RegLic.exe program will save the license as C:\Program Files\PRIMATTE\OFX\Primatte.lic

NOTE: You can copy the lines above or below the license key characters as long as they have the 'hash mark' or'number sign' at the beginning of the line.

NOTE: Please do not change the name or location of the Primatte License File: field. The license will not be recognized if you do.

▪ Check the message at the bottom of the window. If you see Registration Complete there, Primatte for OFX is unlocked and activated. If you do not see Registration Complete, please e-mail sgross@imagica-la.com and tell Scott the error message that appears.

▪ Exit the Reglic.exe application and launch your host OFX application.

Install the license on a Linux system:

▪ In the /usr/local/PRIMATTE/OFX/license/ directory you will find a Linux utility named RegLic. Once you have your license, execute the RegLic program. Enter the Registration License that was e-mailed to you in the window area provided (it is usually easier to copy and paste the license from your e-mail to avoid transcription errors). Click on the Registration button and the RegLic program will save the license as /usr/local/PRIMATTE/OFX/Primatte.lic.

NOTE: You can copy the lines above or below the license key characters as long as they have the 'hash mark' or'number sign' at the beginning of the line.

NOTE: Please do not change the name or location of the Primatte License File: field. The license will not be recognized if you do.

▪ Check the message at the bottom of the window. If you see Registration Complete there, Primatte for OFX is unlocked and activated. If you do not see Registration Complete, please e-mail sgross@imagica-la.com and tell Scott the error message that appears.

▪ Exit the Reglic application and launch your host OFX application.

Install the license on an SGI IRIX system:

▪ In the /usr/local/PRIMATTE/OFX/license/ directory you will find an IRIX utility named RegLic. Once you have your license, execute the RegLic program. Enter the Registration License that was e-mailed to you in the window area provided (it is usually easier to copy and paste the license from your e-mail to avoid transcription errors). Click on the Registration button and the RegLic program will save the license as /usr/local/PRIMATTE/OFX/Primatte.lic.

NOTE: You can copy the lines above or below the license key characters as long as they have the 'hash mark' or'number sign' at the beginning of the line.

NOTE: Please do not change the name or location of the Primatte License File: field. The license will not be recognized if you do.

▪ Check the message at the bottom of the window. If you see Registration Complete there, Primatte for OFX is unlocked and activated. If you do not see Registration Complete, please e-mail sgross@imagica-la.com and tell Scott the error message that appears.

▪ Exit the Reglic application and launch your host OFX application.

Install the license on an Apple OSX system:

▪ In the /usr/local/PRIMATTE/OFX/license/ directory you will find an OSX utility named RegLic. Once you have your license, execute the RegLic program. Enter the Registration License that was e-mailed to you in the window area provided (it is usually easier to copy and paste the license from your e-mail to avoid transcription errors). Click on the Registration button and the RegLic program will save the license as /usr/local/PRIMATTE/OFX/Primatte.lic.

NOTE: You can copy the lines above or below the license key characters as long as they have the 'hash mark' or'number sign' at the beginning of the line.

NOTE: Please do not change the name or location of the Primatte License File: field. The license will not be recognized if you do.

▪ Check the message at the bottom of the window. If you see Registration Complete there, Primatte for OFX is unlocked and activated. If you do not see Registration Complete, please e-mail sgross@imagica-la.com and tell Scott the error message that appears.

▪ Exit the Reglic application and launch your host OFX application.

Where the plug-ins are installed:

▪ On a 32-bit Windows system = C:\Program Files\Common Files\OFX\Plugins\Primatte.ofx.bundle\Contents\Win32\

▪ On a 32-bit Linux system = /usr/OFX/Plugins/Primatte.ofx.bundle/Contents/Linux-x86/

▪ On a 64-bit Linux system = /usr/OFX/Plugins/Primatte.ofx.bundle/Contents/Linux-x86-64/

▪ On an IRIX system = /usr/OFX/Plugins/Primatte.ofx.bundle/Contents/IRIX64/

▪ On a Apple Macintosh OSX system = /usr/OFX/Plugins/Primatte.ofx.bundle/Contents/MacOS/

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3. Accessing the Primatte plug-in from your OFX application

NOTE: This document will only apply to the Assimilate SCRATCH application. Other Primatte for OFX manuals specific to new host applications will be created in the future. Since the tool set and functionality of the Primatte for OFX plug-in remains basically the same for all hosts, we hope that this manual will help users learn the Primatte functionality until additional manuals are created.

3a. Accessing the Primatte plug-in from SCRATCH

▪ Start up SCRATCH.

▪ Import the clip to be chromakeyed. Your SCRATCH widow should look something like this...

▪ Right-click on the clip and choose [Play All] when this menu is displayed...

▪ Your SCRATCH window should now look like this...

▪ Right-click on the image area and choose the Process option.

▪ The bottom area of the window will now look like this...

▪ In the Process area on the left side of the window, select New.. and you will be offered a selection of Processes from which to choose. See Chapter 6 - SCRATCH Process in the SCRATCH User Guide for more details on the Process interface. This Process Selection area will look something like this...

▪ Select the Primatte option then click on the Insert Node.. button. The screen will change again and present you with the Primatte Operation Mode tool menu...

▪ If you wish to add a background image clip or an external garbage matte clip, click on the FX Input(s) button on the left side of the screen in the Process Controls area. This will display a new area where you can add a background and matte...

▪ When you click on the postage stamp area beneath the Background or Matte labels, a white outline will appear telling you that it has been selected. Click on the Load.. button and it will bring up an image browser that will let you click and drag the clip into the selected postage stamp square. Click on the FX Controls button again to get back to the Primatte tool panel.

▪ You are now ready to use the Primatte chromakey plug-in.

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4. Basic Operation Tutorial

NOTE: This describes the operation of the Primatte plug-in. A more detailed explanation of how the Primatte algorithm actually works can be found in Section 10 of this manual.

▪ The Primatte plug-in interface area will appear as shown below...

NOTE: Since the SCRATCH interface forces the user to scroll to see all the Primatte tools, this image has been created to show you the entire tool set...

▪ The basic functionality for the Primatte plug-in interface is centered around the Operation Mode selector. If you click on it, you will see the 15 main Primatte Operation Modes. Only four to six are used regularly but the others may come in handy at some time or other.

▪ There are four main steps to using the Primatte plug-in and Select BG Color is the first step. This comes up as the default mode when the plug-in is first accessed.
NOTE: This version of Primatte has a new feature that may eliminate the first three steps of using Primatte. It is called the Auto-Compute button and may make your keying operation much easier. You can click on this button as a first step and it may automatically sense the backing screen color, eliminate it and even get rid of some of the foreground and background noise that would normally be cleaned up in Steps 2 (Clean BG Noise) and 3 (Clean FG Noise) of the Primatte operation. If you get good results then click here to jump ahead to the spill removal tools.

NOTE: The Auto-Compute button has two sliders that modify its behavior; the Auto BG Factor and the Auto FG Factor sliders. These may be moved to get better results with the Auto-Compute button.

▪ Position the cursor in the bluescreen area (or whatever background color you are using), somewhere near the foreground object. Select an area to sample the targeted background color. Depending on whether your Pick mode Selector has Point or Bounding Box selected, you will get either a rectangular selection area or a string of points (snail trail). Release the mouse button (or let up on the stylus) and Primatte will start the compositing process. If the foreground shot was done under ideal shooting conditions, Primatte will have done 90-95% of the chromakeying in this one step.

TIP: If you made a large rectangle in the blue area, Primatte averages the multi-pixel sample to get a single color to adjust to. Sometimes Primatte works best when only a single pixel is sampled instead of a range of pixels. The color selected at this point in the procedure is critical to the operation of the plug-in from this point forward. Should you have difficulties further along in the tutorial after doing a range of blue shades, Reset the Primatte operation and try the Select BG Color Operation mode again with a single dark blue shade or single light blue shade.

TIP: If the foreground image has a shadow in it that you want to keep in the composite, do not select any of the dark blue pixels in the shadow and it will come along with the rest of the foreground image.

▪ The second and third steps in using Primatte require viewing the alpha channel or ’matte view’ of the image in the main SCRATCH view window. Click on the View mode selector and choose the Matte view. The display window will show a black and white view of the matte being created by Primatte.

▪ Change the Operation Mode from Select BG Color to Clean BG Noise . If there are any white regions in the dark, `bluescreen area', it is noise and should be removed. Move the cursor through these areas if using the Point (or Snail Trail) sampling method or make a box around them if using the Bounding Box sampling method and sample these whitish noise regions. Each time you let up on the mouse (or stylus) button, Primatte will process the data and eliminate the noise. Repeat this as often as necessary to clear the noise from the background areas. Sometimes increasing the brightness of your monitor or the screen gamma allows you to see noise that would otherwise be invisible.

Before Background noise removal After Background noise removal

TIP: When clearing noise from around loose, flying hair or any background/foreground transitional area, be careful not to select any of areas near the edge of the hair. Leave a little noise around the hair as this can be cleaned up later using the Fine Tuning Sliders tool.

NOTE: You do not need to remove every single white pixel to get good results. Most pixels displayed as a dark color close to black in a key image will become transparent and virtually allow the background to be the final output in that area. Consequently, there is no need to eliminate all noise in the bluescreen portions of the image. In particular, if an attempt is made to meticulously remove noise around the foreground object, a smooth composite image is often difficult to generate.

▪ If there are dark regions in the middle of the mostly white foreground object, that is, if the key is not 100% in some portion of the targeted foreground, choose Clean FG Noise from the Operation Mode pop-up menu.

▪ Use the same techniques as for Clean BG Noise, but this time sample the dark pixels in the foreground area until that area is as white as possible.

Before Foreground Noise Removal After Foreground Noise Removal

▪ These were the steps necessary to create a clean matte or key view of the image. With this key, the foreground can be composited onto any background image. However, if there is `spill' on the foreground object from light that was reflected off the background, a final operation is necessary to get a more natural looking composite.

▪ For the fourth step in the Primatte operation return the display monitor to the Composite view by again clicking on the View mode selector and change the view to Composite . This will return the image in main SCRATCH view window to a Composite view and show you the results of the noise removal procedure.

▪ The sample image below has gone through the first three steps and has examples of spill. Notice the blue fringe to her hair and a blue tint on her right cheek, arm and chest.

▪ This is what the image will look like if you had added a background image to the construct.

Note: If you go to the Processed FG view mode, the image may look like this:

Note: The Processed FG view is like a composite done with an alpha blender node when creating a DVE effect. The view shows the foreground against a black background usually with a lot of false coloring or noisy pixels around it. The noisy pixels are generated to maintain the fine hair or thin foreground detail. Because the matte around the noisy pixels are very small and will be multiplied against the noise, the end result will be highly desirable. The main purpose of outputting the processed foreground is for ’multi-layered compositing’. If the compositing artist uses the matte and foreground to make a composite, a bluish edge may appear in the resulting image. The artist should use the matte and processed (or blue-suppressed) foreground for the best results.

▪ There are three ways to remove the spill color. The three spill removal methods are described in the following :

Spill Removal - Method #1 - The Spill Sponge

▪ The quickest method to remove spill is to select the Spill Sponge button from the Operation Mode selector and then sample the spill areas away. By just positioning the cursor over a bluish pixel and selecting it, the blue will disappear from the selected color region and be replaced by a more natural color. Additional spill removal should be done using the Fine Tuning Sliders feature or the Spill(-) feature. Both are explained further on in this manual.
Note: The disadvantage to the Spill Sponge is that it can only be used one time in a particular color region. If the amount of spill removed in the first click is not enough or too much, the Spill(-) tool explained in the Spill Method #3 - The Incremental Spill Tools section below should be used for a more modifiable adjustment.
Note: All spill removal/replacement operations in Primatte can be modified using the Background Spill Replacement tools. Spill can be replaced with either the complement of the background color, a solid color selected by the user or by colors brought from a defocused copy of the background. Depending on the spill conditions, one of these options should provide the results you are looking for. See the information in ??. Spill Replacement Options for more details.

Note: Primatte's spill removal tools work on 'color regions'. In the image above, samples should be made on the light flesh tones, the dark flesh tones, the light blonde hair, the dark blonde hair and the red blouse color regions. One sample in each color region will remove spill from all similar colors in the foreground image.

Spill Removal - Method #2 - The Fine Tuning Sliders

▪ Select the Fine Tuning Sliders button under the Operation Mode selector.

▪ Using the zoom and pan capabilities of the SCRATCH application, zoom into an area that has some blue edges.

▪ Using the cursor, sample a range of the blue pixels that you want to remove. When you let up on the pen or mouse button, Primatte will register the color selected in the From Tune color chip just below the S-poly (Detail) slider. For most images, the L-poly (Spill) slider is all that is required to remove any remaining bluespill. The more to the right the slider moves (the positive direction), the more background screen color will be removed from the sampled pixels. The more to the left (negative direction) the slider moves, the more the selected pixels will move toward the original foreground image's color. The sliding operation is performed by clicking on the L-poly (Spill) button and rotating the pen or mouse clockwise or counter-clockwise to change the value.

Note: You can also just click on the slider and a direct entry windoid will open that will allow you to enter a value.

Note: When using the slider in the Fine Tuning Sliders mode to remove spill, spill color replacement will be replaced based on the setting of the Spill Replacement Buttons. See Spill Replacement Buttons for more information in Chapter ??. Primatte Tools and Buttons.

Note: In the Fine Tuning Sliders mode, re-computation of the composite image will not be accomplished if the pressure-sensitive pen is released too slowly.

TIP: It is better to make several small adjustments to the bluespill areas than a single major one. By this I mean select a light flesh tone and remove the spill and then select a dark flesh tone and remove the spill from it. It is not recommended to sample all the flesh tones that contain spill and try to make a correction. You may end up with undesirable artifacts.

▪ You can use the other two sliders in the same way for different key adjustments. The S-poly (Detail) slider controls the matte softness for the color which is closest to the background color. For example, you can recover lost rarefied smoke in the foreground by selecting the Fine Tuning Sliders mode, clicking on the area of the image where the smoke just starts to disappear and moving the S-poly (Detail) slider to the left. The M-poly (Trans.) slider controls the matte softness for the color which is closest to the foreground color. For example, if you have thick and opaque smoke in the foreground, you can make it semi-transparent by moving the M-poly (Trans.) slider to the right after selecting the pixels in the Fine Tuning Sliders mode.

TIP: If the foreground image changed color dramatically during the fine tuning process, you can recover the original color by selecting an area of the off-color foreground image and moving the L-poly (Spill) slider slightly to the left. This may introduce bluespill back into that color region. Again, use the Fine Tuning Sliders option to suppress the blue, but make smaller adjustments this time.

Spill Removal - Method #3

▪ Select the Spill(-) mode under the Operation Mode selector.

▪ Using the zoom and pan capabilities of the SCRATCH application, zoom into an area that has some blue edges.

▪ Position the cursor over a color region with some spill and click on that area. A small amount of spill will be removed. Continue clicking and more and more spill will be removed. Continue until the desired effect is achieved.

Note: If to much spill is removed and artifacting occurs, select the Spill(+) mode under the Operation Mode selector and click on the same region. The Spill(-) process will be reversed and the image color will return toward the original coloring. More information about the Incremental Adjustment Tools is included below under Section ??. Repeatable Sampling Tools.

Note: If these final 'spill suppression' operations have changed the final compositing results, you may have to return to earlier operations to clean up the matte. If the Composite view looks good, it is a good idea to go back and take a final look at the Matte view. Sometimes in the Primatte operation, a 100% foreground area will become slightly transparent. You can clean those transparent areas up by using the Matte Sponge button. After selecting the Matte Sponge Operation Mode, just click on the transparent pixels and they will become 100% foreground. All of the spill-suppression information will remain intact. Alternatively, you can go to the Matte view and then using the Fine Tuning Sliders option, select those transparent areas and move the M-poly (Trans.) slider slightly to the left. This will move that color region from 0-99% foreground with spill suppression to 100% foreground with spill suppression and should solve the problem. The Matte(+) tool will also work to solve this problem.

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5. Repeatable Sampling Tools

▪ Most of the Primatte operations are done using a 'mouse sampling' operation. The only exceptions are the Fine Tuning Sliders Operation Mode and its sliders. The Fine Tuning operation gives a continuous valuator for fine-tuning but some of the sliders are not often used because results are often unpredictable.

Note: Another weak point in previous versions of Primatte is the lack of functionality to attenuate and thicken the existing matte density. This version of Primatte offers a more intuitive, easy-to-use and powerful user interface called the Repeatable Sampling Operation Tools .

In addition to the conventional Primatte Operation Modes, six new modes are added:

▪ Spill(+) ▪Spill(-)

▪ Matte(+) ▪ Matte(-)

▪ Detail(+) ▪ Detail(-)

The Spill Sampling Tools

▪ Using the Spill(+) and Spill(-) modes, you can gradually remove or recover the spill intensity on the foreground object by sampling the referenced color region repeatedly. The conventional Spill Sponge tool removes the spill component in a single action at one level and did not allow sampling the same pixel a second time. Even though just a small amount of spill needed to be removed, the spill sponge removed a preset amount without allowing any finer adjustment.

Effect of Spill(+/-) Repeatable Sampling

▪ Using the zoom and pan capabilities of the Scratch application, zoom into an area that has some blue edges and click on a pixel with some spill on it. Repeated clicking will incrementally remove the spill. Continue this operation until the desired result is achieved.

The Matte Sampling Tools

▪ The Matte(+) and Matte(-) modes are used to thicken or attenuate the matte information. If you want a thinner shadow on a foreground object, you can use the Matte(-) mode as many times as you like to make it more transparent. On the other hand, you can use the Matte(+) mode to make the matte thicker in that color region.

Effect of Matte(+/-) Repeatable Sampling

The Detail Sampling Tools

▪ The Detail(+) and Detail(-) modes are a refined version of Clean BG Noise and Restore Detail. For example, when you see some dilute noise in the backing area but don't want to remove it completely because it affects some fine detail in a different area, try using Detail(-). It will attenuate the noise gradually as multiple samples are made on the pixel. You should stop the sampling when important fine details start to disappear.

Effect of Detail(+/-) Repeatable Sampling

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6. Spill Replacement Options

The proper processing of spill on foreground objects is one of the many useful features of Primatte. There are now three spill processing methods whereas older versions of the Primatte product supported only one or two of them. The three methods are as follows:

- Complement Spill Replacement

- Solid Color Spill Replacement

- Defocus Spill Replacement

Note: After the first three steps of Primatte have been performed, you can switch between the three methods below and actually see the difference in results when looking at the Composite View. This may be helpful in learning to understand the differences between the three modes.

Complement Replacement mode:

▪ This is the default spill replacement mode. This mode will maintain fine foreground detail and deliver the best quality results. If foreground spill is not a major problem, this mode is the one that should be used.

Complement Replacement mode Maintains Fine Detail.

▪ The Complement Replacement mode is sensitive to foreground spill. If the spill intensity on the foreground image is rather significant, this mode may often introduce serious noise in the resultant composite as in the example below...

Solid Color Replacement mode

Solid Color Replacement mode:

▪ In the Solid Color Replacement mode, the spill component will be replaced by a 'user defined' palette color. While the Complement Replacement mode uses only the backing color complement to remove small amounts of spill in the original foreground, the Solid Color Replacement mode tries to assuage the noise using the 'user defined' palette color. Changing the palette color for the solid replacement, the user can apply good spill replacement that matches the composite background. Its strength is that it works fine with even serious blue spill conditions. In the example above and below, a gray color was chosen to replace the spill and a more natural result was obtained.

Smooth Spill Processing with Solid Color Replacement

▪ On the negative side, when using the Solid Color Replacement mode, fine detail on the foreground edge tends to be lost. The single palette color sometimes cannot make a good color tone if the background image has some high contrast color areas.

Defocus Replacement mode

▪ The Defocus Replacement mode uses a defocused copy of the background image to determine the spill replacement colors instead of a solid palette color or just the complement color. This mode can result in good color tone on the foreground object even with a high contrast background. As in the example below, spill can even be removed from frosted glass using this feature and still retain the translucency.

▪ On the negative side, the Defocus Replacement mode sometimes results in the fine edge detail of the foreground objects getting lost. Another problem could occur if the user wanted to later change the size of the foreground image against the background. Since the background/foreground alignment would change, the applied color tone from the defocused image might not match the new alignment.

Blue Suppression of a Frosted Glass Object

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7. Inward Defocus Feature

A method of defocusing the matte where the softening is only applied inwardly, toward the center of the foreground subject. The default Primatte defocus feature affects the matte edges in both directions (inward and outward) and sometimes introduced a halo artifact around the foreground object's edge in the composite view. This was most evident when using the Complement Replacement mode. With the Inward Defocus switch selected Inward, the matte defocus functions only in the inward direction of the foreground subject (toward the center of the white area). The final result is that it removes small and dark noise in the backing area without picking them up again in the Clean BG Noise mode and sometimes results in softer, cleaner edges on the foreground objects and no halo effect around the foreground object.

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8. External Matte Input

Primatte accepts a black & white clip as an external matte to hide the unnecessary garbage like light arms, microphones and other undesirable foreground objects. Areas that are white in the garbage matte clip will take the pixels from the background and areas that are black will be from the composite image. The matte is added to Matte FX Input in Scratch and can be activated by clicking on the Ext. Matte button.

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9. Primatte Tools and Buttons

Auto-Compute Tools

The Auto-Compute tools can be used as the first step in the Primatte operation. It's purpose is to try and do the first three steps of the Primatte operation for you. It will try to automatically detect the backing screen color, remove it and do some clean-up on the foreground and background noise. If the clip was shot with an evenly lit, well saturated backing screen, the Auto-Compute button will leave you with an image that may only need some spill removal to complete your keying operation.

Auto-Compute Button

The Auto-Compute button is used to activate the Auto-Compute feature.

Auto FG Factor Slider

The AutoFG Factor slider can be used to modify how the Auto-Compute algorithm deals with foreground noise. Change the position of this slider and you can see the results of the Auto-Compute operation change.

Auto BG Factor Slider

The Auto BG Factor slider can be used to modify how the Auto-Compute algorithm deals with background noise. Change the position of this slider and you can see the results of the Auto-Compute operation change.

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Operation Mode Selector Tools

Select BG Color

When this Operation Mode is selected, the Primatte operation will be initially computed by having the user sample the target background color within the image window. For keying operations, this is the first step and should be followed by the steps described immediately below. The color selected will be displayed in the Backing Color indicator (see description below).

Clean BG Noise

When this Operation Mode is selected, the user samples pixels on the image window known to be 100% background. White noisy areas in the 100% background region will become black. This is usually the second step in using Primatte.

Clean FG Noise

When this Operation Mode is selected, the user samples pixels on the image window known to be 100% foreground. The color of the sampled pixels will be registered by Primatte to be the same color as in the original foreground image. This will make dark gray areas in the 100% foreground region become white. This is usually the third step in using Primatte.

Matte Sponge

When this Operation Mode is selected, the sampled color within the image window becomes 100% foreground. However, if the sampled color is already keyed out and removed, it leaves the current 'suppressed' color. It only affects the key or matte information. This tool is usually used to quickly remove stray transparent pixels that have appeared during the chromakeying procedure. It is a quick and easy way to make final adjustments to a composite.

Make FG Transparent

When this Operation Mode is selected, the opaque foreground color region sampled in the image window becomes slightly translucent. This operation is useful for the subtle tuning of foreground objects which are otherwise 100 percent covered with smoke or clouds. It can only be used one time on a particular color. For a more flexible way to thin out a color region and be able to make multiple samples, you should use the Matte(-) tool. It expands the medium polyhedron slightly.

Restore Details

With this mode selected, the completely transparent background region sampled in the image window becomes translucent. This operation is useful for restoring lost hair details, thin wisps of smoke and the like. It shrinks the small polyhedron slightly.

Spill Sponge

When this Operation Mode is selected, the background color component in the sampled pixels (or spill) within the image window is keyed out and removed for the color region selected. This operation can only be used once on a particular color and the amount of spill suppression applied is not adjustable. It is the fastest way to remove spill from a composite image. For more accurate spill suppression, a Fine Tuning Sliders or Spill(+) operation should follow or be used instead. This can usually be the fourth (and final) step in using Primatte unless additional adjustments are necessary.

Spill(+)

When this Operation Mode is selected, color spill will be returned to the sampled pixel color (and all colors like it) in the amount of one Primatte increment. This tool can be used to move the sampled color more in the direction of the color in the original foreground image. It can be used to nullify a Spill(-) step. This tool dents the Primatte large polyhedron in the color region sampled.

Spill(-)

When this Operation Mode is selected, color spill will be removed from the sampled pixel color (and all colors like it) in the amount of one Primatte increment. If spill color remains, another click using this Operation Mode will remove more of the color spill. Continue using this tool until all color spill has been removed from the sampled color region. This tool expands the Primatte large polyhedron in the color region sampled.

Matte(+)

When this Operation Mode is selected, the matte will be made more opaque for the sampled pixel color (and all colors like it) in the amount of one Primatte increment. If the matte is still too translucent or thin, another click using this Operation Mode will make the sampled color region even more opaque. This can be used to thicken smoke or make a shadow darker to match shadows in the background imagery. It can only make these adjustments to the density of the color region on the original foreground image. It can be used to nullify a Matte(-) step. This tool dents the Primatte medium polyhedron in the color region sampled.

Matte(-)

When this Operation Mode is selected, the matte will be made more translucent for the sampled pixel color (and all colors like it) in the amount of one Primatte increment. If the matte is still too opaque, another click using this Operation Mode will make the sampled color region even more translucent. This can be used to thin out smoke or make a shadow thinner to match shadows in the background imagery. This tool expands the Primatte medium polyhedron in the color region sampled.

Detail(+)

When this Operation Mode is selected, foreground detail will become less visible for the sampled pixel color (and all colors like it) in the amount of one Primatte increment. If there is still too much detail, another click using this Operation Mode will make more of it disappear. This can be used to remove smoke or wisps of hair from the composite. Sample where is visible and it will disappear. This is for moving color regions into the 100% background region. It can be used to nullify a Detail(-) step. This tool expands the Primatte small polyhedron in the color region sampled.

Detail(-)

When this Operation Mode is selected, foreground detail will become more visible for the sampled pixel color (and all colors like it) in the amount of one Primatte increment. If detail is still missing, another click using this Operation Mode will make detail more visible. This can be used to restore lost smoke or wisps of hair. Sample where the smoke or hair just disappears and it will return to visibility. This is for restoring color regions that were moved into the 100% background region. It may start to bring in background noise if shooting conditions were not ideal on the foreground image. This tool dents the Primatte small polyhedron in the color region sampled.

Fine Tuning Sliders

When this Operation Mode is selected, the color of the sampled pixel within the image window is registered as a reference color for fine tuning. It is displayed in the Color Chip below the S-poly (Detail) slider. To perform the tuning operation, sample a color region on the image, select a Fine Tuning slider and move the slider to achieve the desired effect. See the Fine Tuning Sliders tool descriptions further on in this chapter for more details on slider selection.

3D Sample

This Operation Mode is used when you have opened the 3D Viewer window to observe the operation of the Primatte algorithm (See Chapter 9. The 3D Viewer). With this mode selected, any pixels sampled on the image window will be displayed as a spray of pixels in the 3D Viewer window. It can be used to get an idea where the color range selected of the pixels selected are in relation to the polyhedrons. As you make different samples on various colors in the image window, you will see the white spray of pixels move around on the 3D Viewer.

Backing Color Indicator

The color selected after using the Select BG Color Operation Mode will be displayed in the Backing Color indicator.

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View mode Popup Menu -

Composite View

This changes the view in the viewport to a grayscale image representing the Composite output of the Primatte node.

Matte View

This changes the view in the viewport to a grayscale image representing the Matte output of the Primatte node.

Processed Foreground View

This button displays the processed foreground view in the main SCRATCH window. It only displays the output of the Primatte node and not the background image (even if one is attached to the node). The view shows the foreground against a black background usually with a lot of false coloring or noisy pixels around it. The noisy pixels are generated to maintain the fine hair or thin foreground detail. Because the matte around the noisy pixels are very small and will be multiplied against the noise, the end result will be highly desirable. The main purpose of outputting the processed foreground is for ’multi-layered compositing’. If the compositing artist uses the matte and foreground to make a composite, a bluish edge may appear in the resulting image. The artist should use the matte and processed (or blue-suppressed) foreground for the best results.

Foreground View

This changes the view in the viewport to the original foreground image.

Background View

This changes the view in the viewport to the original background image.

External Matte View

This changes the view in the viewport to the External Matte image that you may have added in the Process Controls section of SCRATCH.

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Algorithm Popup Menu

NOTE: For more details on the three Primatte algorithms, click here.

Primatte

The Primatte algorithm mode delivers the best results and supports both the Solid Color and the Complement Color spill suppression methods. It is the algorithm that uses three multi-faceted polyhedrons (as described further down in the this document) to separate the 3D RGB colorspace. It is also the default algorithm mode and, because it is computationally intensive, it may take the longest to render.

Primatte RT

Primatte RT is the simplest algorithm and therefore, the fastest. It uses only a single planar surface to separate the 3D RGB colorspace and, as a result, does not have the ability to separate out the foreground from the backing screen as carefully as the above Primatte algorithm. Other disadvantages of the Primatte RT algorithm is that it does not work well with less saturated backing screen colors and it does not support the Complement Color spill suppression method.

Primatte RT+

Primatte RT+ is in between the above two options. It uses a six planar surface color separation algorithm and will deliver results in between the other two in both quality and performance. Other disadvantages of the Primatte RT+ algorithm is that it does not work well with less saturated backing screen colors and it does not support the Complement Color spill suppression method.

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Fine Tuning Sliders

From/To Indicators

When in the Fine Tuning Sliders Operation Mode, these indicated the selected 'color region of interest'. Before using a Fine Tuning Slider, you must indicate to the software what color region you want to modify. After selecting a color region, this indicator displays that selected color region.

L-poly Slider (Spill Removal)

When in the Fine Tuning Sliders Operation Mode, this slider can be used to remove spill from the registered color region. After choosing the Fine Tuning Sliders Operation Mode and selected a color region, this slider can be moved to remove spill from the registered color region. The more to the right the slider moves, the more spill will be removed. The more to the left the slider moves, the closer the color component of the selected region will be to the color in the original foreground image. If moving the slider all the way to the right does not remove all the spill, re-sample the color region and again move the slider to the right. These slider operations are additive. This result achieved by moving the slider to the right can also be achieved by clicking on the color region using the Spill(-) Operation Mode. This slider bulges the Primatte large polyhedron near the registered color region.

M-poly Slider (Transparency)

When in the Fine Tuning Sliders Operation Mode, this slider can be used to make the matte more translucent in the registered color region. After choosing the Fine Tuning Sliders Operation Mode and selected a color region, moving this slider to the right makes the registered color region more transparent. Moving the slider to the left makes the matte more opaque. If moving the slider all the way to the right does not make the color region translucent enough, re-sample the color region and again move the slider to the right. These slider operations are additive. This result achieved by moving the slider to the right can also be achieved by clicking on the color region using the Matte(-) Operation Mode. This slider bulges the Primatte medium polyhedron near the registered color region.

S-poly Slider (Restore Lost Detail)

When in the Fine Tuning Sliders Operation Mode, this slider can be used to restore lost detail. After choosing the Fine Tuning Sliders Operation Mode and selected a color region, moving this slider to the left makes the registered color region more visible. Moving the slider to the left makes the color region less visible. If moving the slider all the way to the left does not make the color region visible enough, re-sample the color region and again move the slider to the left. These slider operations are additive. This result achieved by moving the slider to the left can also be achieved by clicking on the color region using the Detail(-) Operation Mode. This shrinks the small polyhedron (which contains all the blue or green background colors) and releases pixels that were close to the background color. The Small Polyhedron Slider in the Fine Tuning Sliders mode is useful for restoring pixels that were lost because they were so similar to the background color. This slider dents the Primatte small polyhedron near the registered color region.

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Spill Replacement Tools

A more detailed explanation of the Spill Replacement Tools is in the Chapter 6. Spill Replacement options section above. Click here to go to that section.

Spill Replacement Selector

This pop-up menu displays the three spill replacement modes and allows the user to choose between them:

Solid Color Replacement - Replaces the spill color with a 'user selected' solid color.

Complement Replacement - Replaces the spill color with the complement of the backing screen color.

Defocus Replacement - Replaces the spill color with colors from a defocused version of the background image.

Solid Color Spill Replacement Color Chip

This color chip displays the current Solid Color Spill Replacement Color (by default, it is gray; R128, G128, B128). By selecting Solid Color Replacement and then clicking on this color chip, the Scratch color wheel is displayed allowing the user to select a solid color to be used in replacing colorspill.

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Matte Adjustment Tools

External Matte Button

This button, when selected, activates the external matte input of the Primatte plug-in (if one has been created and attached). The white area of the third input to Primatte will be classified as 100% transparent regardless of the original FG information.

Defocus Value

This tool is used to soften a hard-edge that might sometime occur after keying out the background. Moving the slider in a positive direction determines the defocusing level being applied to the matte. The direction of the blur can be modified by the Defocus Dir. Selector (see next tool description).

Note: With using this feature, foreground details and smoothness of motion blur may be adversely affected. Set it to 0 for optimum results.

Defocus Dir.

This selector allows the user to choose between having the Defocus Matte Slider affect the matte edges in either one or two different directions. The two options for defocus direction are Inward for inward direction only and Outward where the blur is applied in both the inward and outward directions. See 7. Inward Defocus Feature for more information about this feature or click here.

Note: With using this feature, foreground details and smoothness of motion blur may be adversely affected. Set it to 0 for optimum results.

Inward Direction

This blurs the edges of the matte only in the inward direction.

Outward Direction

This blurs the edges of the matte in both the inward and outward direction.

Shrink

Determines the degree of background penetration into the foreground around the silhouette of the foreground object. The effect is likened to ’shrinking’ the matte.

Note: With using this feature, foreground details like wisps of hair and smoothness of motion blur may be adversely affected. Set it to 0 for optimum results.

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Pick Mode Tools

Which when selected brings up a pop-up menu that looks like this...

T

This tool is used to select the preferred method of sampling pixels on an image window...

Bounding Box

When Bounding Box is selected, the user clicks and drags to create a rectangular selection area. When using the Select BG Color, Spill +/-, Detail +/-, Matte +/- tools, the selection is then created from the average of all the pixels in the rectangular area. The rest of the operations (e.g. Clean BG Noise, Clean FG Noise, etc.), take account of all the pixels in the rectangular region.

Point

A Point selection is like a trail of pixels selected as the cursor moves over the image. It is sometimes called a 'snail trail' or XOR sample. Point selection is similar to Bounding Box, in that it averages or uses all the pixel information of the trail dependent on the operation.

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Grain Tools

The Grain Tools are used when a foreground image is highly compromised by film grain. As a result of the grain, when backing screen noise is completely removed, the edges of the foreground object often become harsh and jagged leading to a poor key. These tools were created to, hopefully, help when a compositing artist is faced with a grainy image.

Grain Size

The Grain Size selector gives the user a range of grain removal from Small to Large. The use of this tool is explained further along in this section.

When the Grain Size tool is selected, it brings up a pop-up menu that looks like this...

If the foreground image has a large amount of film grain induced pixel noise, you may loose a good edge to the foreground object when trying to clean all the grain noise with the Clean BG Noise Operation Mode. These tools allow the user t clean us the grain noise without affecting the quality of the key. A short tutorial explaining when and how to use these tools is at the end of this section. Click here to go to the tutorial.

None

When None is selected, the user gets the color of the exact pixel sampled.

Small

When Small is selected, the user gets the average color of a small region of the area around the sampled pixel. This should be used when the grain is very dense.

Medium

When Medium is selected, the user gets the average color of a medium-sized region of the area around the sampled pixel. This should be used when the grain is less dense.

Large

When Large is selected, the user gets the average color of a larger region of the area around the sampled pixel. This should be used when the grain is very loose.

Grain Tol.

Adjusting this slider this should increase the affect of the Clean BG Noise tool without changing the edge of the foreground object.

Grain Tools Tutorial

If you have a noisy image as in the example below...

...you will find that the matte is also noisy:

Currently you can use the Clean BG Noise Operation Mode to remove the noisy pixels, but this can also modify the edge of the foreground object in a negative manner.

Using the Grain Tools in the following way may help you clean up the image and still get a good edge on the matte:

1. Use the Clean BG Noise Operation Mode just a small mount to remove some of the white noise in the Matte View but do use it so much that you affect to the edge of the foreground object.

2. Then select the Grain Size tool and select Small as a first step to reduce the grain:

With the Grain Tol. slider set at 0, move it around some. This should increase the affect of the Clean BG Noise tool without changing the edge of the foreground object.

Sometimes this may not be enough to totally remove the grain so by adjusting the Grain Tol. slider, you can tell the Primatte algorithm what brightness of pixels you think is grain. You should try not to use too high of a value otherwise it will affect the overall matte. For an example of an 'over adjusted' image see below...

The Primatte grain algorithm uses a 'Defocused Foreground' image to compute the noise. You can see the results of the defocused foreground by changing the View Mode to Defocus FG :

NOTE: The Small, Medium and Large settings for the Grain Tool all produce defocused foregrounds that have larger blurs respectively.

NOTE: It is important to make sure that the crop settings are correctly applied otherwise when the defocus image is generated, if there is 'garbage' on the edges of the images, then that garbage will be blurred into the defocus foreground.

As a review:

1. Select the Select BG Color Operation Mode and click on a backing screen color.

2. Select the Clean BG Noise Operation Mode and use it sparingly so that it has minimum affect to the edge of the foreground object.
3. If there is still grain in the backing screen area, then use the Grain Size functionality starting at the Small setting to reduce the grain

4. If the grain is still present, then try increasing the Grain Tol. slider a little - not too much.

5. If grain is still a problem then try changing the Grain Size to Medium of Large and also changing the grain tolerance until the desired effect is achieved.

NOTE: The grain functionality does not always remove grain perfectly but is sometimes useful to minimize its effects.

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Crop Sliders

These 4 sliders are used to create a rectangular garbage matte. All pixels outside of the rectangle will be forced to 100% background pixels.

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3D Viewer

This button opens a window that displays the Primatte algorithms and allows the user to see what is happening as he uses the various Primatte tools. It is a passive feature that has no adjustment capabilities, it may prove useful in evaluating an image as you operate on it.

When you select it, you are presented with a window that may look similar to one of these images (depending on which Primatte algorithm you have selected)...

The different algorithms are described in more detail in the next section of this manual. Here is a description of the tools and features of the 3D Viewer:

3D Viewer Tools

At the top of the 3D Viewer window are three areas that can be clicked on:

1. Clicking and dragging on the blue center area allows the user to move the window around on the screen.

2. Clicking and dragging on the triangular white region in the upper right corner allows the user to scale the 3D Viewer window.

3. Clicking on the square white region in the upper left of the window displays a pop-up menu that looks like this...

NOTE: A selected feature has a solid yellow square next to it. An Unselected feature has a hollow yellow square next to it.

Minimize

This feature, when selected, make the 3D Viewer window disappear. Only the Blue bar at the top of the window remains.

Large Surface

This feature, when selected, displays the large Primatte polyhedron in the viewer window.

Middle Surface

This feature, when selected, displays the medium Primatte polyhedron in the viewer window.

Small Surface

This feature, when selected, displays the small Primatte polyhedron in the viewer window.

Opaque

This feature, when selected, makes the selected polyhedrons opaque. De-selecting it makes them semi-transparent.

Samples

This feature, when selected, allows the user to sample color regions on the image window using the 3D Sample Operation Mode and see where those regions are in relation to the polyhedron and the algorithm. The colors will be displayed as a spray of pixels in the color selected. This button only allows the user to see or clear the sampled colors.

NOTE: The 3D Sample Operation Mode must be selected for this feature to operate. Click here for details on that tool.

Clear BG

This feature changes the background color of the 3D Viewer window from black (when unselected) to transparent (when selected).

Sliced

This feature, when selected, slices open the large and medium polyhedrons so that the inner polys can be seen. When unselected, the largest polyhedron selected becomes a completely closed polyhedron and you cannot see the inner polyhedrons (unless the Opaque feature is deselected).

Wireframe

This feature, when selected, changes the polyhedrons from shaded-surface objects to wireframe objects.

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Help

The Help button opens a web browser and displays this Manual/Tutorial. This document is a collection of files in the directory C:\Program Files\primatte\doc.

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10. More about the Primatte Polyhedral Slicing Algorithms

There are three Primatte algorithms. Here is a chart that shows the main differences between them...

For a description of the Primatte algorithm, go to Section 10a. or click here.

For a description of the Primatte RT+ algorithm, go to Section 10b. or click here.

For a description of the Primatte RT algorithm, go to Section 10c. or click here.

10a. Explanation of how Primatte works...

The Primatte chromakey algorithm is a sophisticated method of color space segmentation that can be easily explained to help a user achieve maximum effectiveness with the tool. Basically Primatte segments all the colors in the foreground image into one of four separate categories. The result is a 'spill suppressed' foreground image and a matte which is used to apply the modified foreground to a suitable background.

Primatte works in 3D RGB color space. Here is a visual representation of the Primatte algorithm after an image has been processed.

By operating the Primatte interface, the user essentially creates three concentric, multi-faceted polyhedrons. These can be pictured as three globes (or polyhedrons or polys), one within the other, which share a common center point. The creation of these polyhedrons separates all possible foreground colors into one of four regions; inside the small polyhedron (1), between the small and medium polyhedrons (2), between the medium and the large polyhedrons (3) and outside the large polyhedron (4).

The four regions created are described as follows:

Region 1 (inside the small polyhedron) - This region contains all of the foreground image colors that are considered 100% background. These are the green or blue or whatever colors that were used as the backing color of the foreground image.

Region 2 (between the small and medium polyhedrons) - This region contains all the foreground colors that are at the edges of the foreground object(s), in glass, glass reflections, shadows, sheets of water and other transparent and semi-transparent color regions. These color regions also have spill suppression applied to them to remove color spill from the backing screen.

Region 3 (between the medium and large polyhedrons) - This region contains all the foreground image colors that are 100% foreground but have spill suppression applied to them to remove color spill from the backing screen. Otherwise they are 100% solid foreground colors.

Region 4 (outside the large polyhedron) - This region contains all the 100% foreground image colors that are not modified from the original foreground image. There is no spill suppression applied to these colors.

In the first step in using Primatte (Select BG Color), the user is asked to indicate the backing color on the original foreground image. The sample should usually be taken from a 'medium shaded' area near the foreground object. By 'medium shaded' area, it is meant that if green is the backing color and the green area of the foreground image has many shades of green ranging from very pale green to almost black, a shade of green in-between these extreme ranges should be chosen. If good results are not obtained using this sample, Primatte should be reset and another sample taken using a slightly darker or lighter shade of green. The first sample of Primatte often determines the final result as the center point of all three polyhedrons is created based on this first sample.

A single pixel may be selected or a range of pixels (snail trail or rectangular sample). If a range of pixels is taken, the sample will be averaged to get a single color sample. This single pixel or averaged color sample then becomes the center of the small polyhedron. A few other shades around that color are included in the original small polyhedron.

NOTE: It is recommended that a single pixel be selected as the first sample as you then have some idea where the center point of the polyhedrons is located. If a box sample or a long snail trail sample is made. You can only guess at the average color that ends up being the center point. You can get an idea how this sample affects the algorithm by resetting the Primatte plug-in, going to the Matte View and clicking around on the green or blue screen area while in the Select BG Color Operation Mode. You can immediately see the results of the initial settings of the polyhedrons in this way.

After making a sample of the backing screen color in the first step, the result is a small golf ball-shaped poly as shown in the following image.

The second step in using Primatte is to clean up the backing color area by adding additional shades of green or blue to the small poly. This second step (Clean BG Noise) is usually executed while viewing the black and white Matte View.

Before BG Noise Removal After BG Noise Removal

While in the Clean BG Noise sampling mode, the user samples the white milky regions as shown in the left-hand image above. As the user samples these regions, they turn to black as shown in the right-hand image above.

What is happening in the Primatte algorithm is that these new shades of green (the white milky areas) are added to the small poly where all the shades of green or blue are moved. The next two images show the new pixels sampled (white dots) in relation to the small poly and the image next to it shows how the small poly extends outward to encompass the newly sampled colors into the small poly.

The advantage of this technique is that the polyhedron distorts to enclose only the shades of green that are in the backing screen. Other shades of green around these colors are left undisturbed in the foreground. Other chromakeyers expand from a golf ball-sized shape to a baseball to a basketball to a beach ball. Since it expands in all directions, many shades of green are relegated to 100% background making it hard to get good edges around the foreground objects.

Now that the user has created a small polyhedron, he must shape the medium and large polys. A default medium and large poly are both automatically created and are then modified based on the next couple of Primatte operations. The third Primatte step (Clean FG Noise) is to sample and eliminate gray areas in the 100% foreground area of the image.

Before FG Noise Removal After FG Noise Removal

Again, the user makes several samples on the dark, grayish areas on the foreground object until it is solid white in color. Primatte is shaping the large polyhedron with each color region that is sampled. Care should be taken in both this and the previous steps to not sample too close to the edges of the foreground object. Getting too close to the foreground object's edges will result in hard edges around the foreground object. Primatte uses these samples to modify and shape the medium and large polys to the desired shape. At this point, the matte or key has been created and would allow the foreground objects to be composited into a new background image.

If the user changes the display mode from the black and white Matte View to the color Composite View, there is usually 'color spill' on the edges (and sometimes the center) of the foreground objects. When on the edges of the foreground object, this spill comes from where the edges of the foreground object blended into the backing color. If it is on the center of the foreground object, it usually results from reflected color from the backing screen. The next Primatte step, either Spill Sponge, Fine Tuning or Spill(-), can now be used to eliminate this spill color.

Let's take a look at what is happening in the Primatte algorithm while this next step is performed. Here is what the various tools in Primatte do to the Polyhedrons when they are used:

As you can see above, the Spill Sponge bulges the large polyhedron in the color region specified. A color region is specified by clicking on the image in a particular area with spill present. For example, if the user clicks on some spill on the cheek of a foreground person, Primatte goes to the section of the large polyhedron closest to that particular flesh tone and bulges the polyhedron there. As a result, the flesh tones move from outside the large poly to in-between the medium and large polys. This is Region 3 and, if you remember, is 100% foreground with spill suppression. As a result of the suppression, the spill is removed from that cheek color and all other shades of that color on the foreground. The user would then continue to sample areas of the image where spill exists and each sample would remove spill from another color region.

When all spill has been removed, the user should have a final composite. As a last step, he should go back to the Matte View and make sure that gray, transparent areas have not appeared in the foreground area. If there are any, the Matte Sponge Operation Mode should be selected and those gray pixels are sampled until they have all turned white again.

The Matte Sponge and Spill Sponge tools bulge or dent the polyhedrons a pre-selected amount. If the desired results are not achieved or the results are too extreme for the image, a manual method can be applied. The user should choose the Fine Tuning sliders, select a color region of interest and then move the appropriate slider to get the desired results.

For example, to remove spill, select a region of the composite image with spill on it. Move the spill or large poly slider to the right a little bit, the large poly will bulge and the spill should disappear. Move it a little more, if necessary. Moving this slider to the right removes spill (moves the colors from outside the large poly to between the medium and large polyhedrons) and moving it to the left, dents the large poly and moves that color region to outside the large poly.

If the user samples a foreground object shadow and then moves the Matte or medium poly slider to the right, the shadow will become more transparent. This is useful for matching composited shadows to shadows on the plate photography. It can also be used to make clouds or smoke more transparent.

If some foreground detail disappears during the composite, the user can select where the detail should be and then move the detail or small poly slider to the left. This dents the small poly in that color region and releases the detail pixels from the small poly into the visible region between the small and medium polyhedrons.

The Spill Sponge and Matte Sponge tools are 'shortcut tools' that automatically move the sliders a pre-selected amount as a timesaving step for the user. Other 'shortcut tools' include the Make FG Trans. tool and the Restore Detail tool.

These 'shortcut tools' are one-step operations where the user clicks on a color region of interest and Primatte performs a pre-calculated operation. Hopefully, most operations using Primatte would only require these tools, but the manual operation of the sliders is always an option.

The Spill(-) tool bulges the large poly a small amount incrementally in the color region that is clicked on and the Spill(+) tool dents it a small amount with each click. The Matte(-) and Matte(+) tools do the same to the medium poly and the Detail(-) and Detail(+) do it to the small poly.

10b. Explanation of how Primatte RT+ works...

The Primatte RT+ algorithm differs from the Primatte algorithm in that it has a six surface color separator instead of the 127-faceted polyhedrons. This makes the Primatte RT+ algorithm much simpler and, therefore, faster to calculate. The results and performance of Primatte RT+ falls in between the Primatte and Primatte RT options. Where the Primatte RT+ algorithm might not work well is with less saturated backing screen colors and it also does not support the Complement Color spill suppression method (which is the spill suppression method that delivers the best detail). For a well-lit and photographed image or clip, this algorithm will produce good results and render quickly.

Here is what a visual representation of the Primatte RT algorithm looks like after an image has been processed...

10c. Explanation of how Primatte RT works...

Primatte RT is the simplest algorithm and, therefore, the fastest. It uses only a single planar surface to separate the 3D RGB colorspace and, as a result, does not have the ability to separate out the foreground from the backing screen as carefully as the above Primatte algorithm. Like the Primatte RT+ algorithm, Primatte RT might not work well with less saturated backing screen colors and it too does not support the Complement Color spill suppression method (which is the spill suppression method that delivers the best detail).. For a well-lit and photographed image or clip, this algorithm will produce good results and render very quickly.

Here is what a visual representation of the Primatte RT algorithm looks like after an image has been processed...

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11. If you have trouble...

Please contact your local Primatte reseller or the IMAGICA technical support person (below):

IMAGICA Technical Support:

Scott Gross

Phone: 1-530-677-9980

FAX: 1-530-677-9981

Cell: 1-530-613-3212

E-mail: sgross@imagica-la.com

Note: Standard support times are between the hours of 7AM and 6PM (Pacific/California Time), but he will try to help you anytime, if possible. Leave a message or a return phone number at the phone number of 1-530-677-9980 and he will get back to you as soon as possible.

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12. Request a Primatte License Key Application Form

Please include the following information:

Company Name:_____________________________________________________

Company Address:__________________________________________________

City:________________________________State/Prov.:____________________

Postal Code:_____________ Country:______________________

Contact Name(s):_____________________________________________

Contact Phone Number:________________________________________

Contact FAX Number:__________________________________________

Contact E-mail Address:________________________________________

Scratch Product Version Number:_____________________________

System MacAddress : ______________________________ (See NOTE: below)

NOTE: To get the MacAddress of your system, download and install the Primatte for OFX plug-in and then go to the C:\Program Files\Imagica\Primatte OFX\ directory and run the GetMac.exe utility. Then e-mail the MacAddress to sgross@imagica-la.com or FAX it to Scott at 1-530-677-9981.

We will e-mail or FAX your license key back to you. Thank you.

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